Deformed high temperature alloys
Deformation high temperature alloy is a class of metal materials based on iron, nickel and cobalt, which can resist oxidation or corrosion in high temperature environment above 600℃, and can work under certain stress for a long time.
Turbine disc is a very important key part on the aero-engine. Although the turbine disk working temperature is lower than the blade, but the working environment is exceptionally complex, and in the core, rim, tenon teeth, groove bottom and web and other parts of the stress, temperature, the degree of media action are different. Therefore, the following typical requirements for turbine disk material performance: high yield strength; sufficient plasticity reserve; sufficient creep, lasting strength and plasticity; high fatigue strength and low circumference fatigue performance; good corrosion resistance, organizational stability and processability. In a word, the overall performance of the material should be good.
Most of the materials used for turbine discs are precipitation-reinforced iron-based or nickel-based deformed high-temperature alloys, and some disc parts are beginning to be prepared by powdered high-temperature alloys, but from the perspective of preparation process and cost, powdered high-temperature alloy turbine discs cannot replace deformed high-temperature alloy turbine discs.
Aero-engine cassette, rotor sealing ring and honeycomb ring parts are more often prepared by low expansion high temperature alloy at home and abroad. Low expansion alloy is the engine to achieve gap control technology, reduce gas loss and improve the thermal efficiency of irreplaceable functional structural materials. Low expansion high temperature alloy is characterized by good overall performance, high strength, low expansion coefficient, almost constant modulus of elasticity, at about 380 ℃ (Curie point) below to room temperature, the alloy thermal expansion coefficient is almost constant. Therefore, the pressurized air receiver prepared by low expansion high temperature alloy is conducive to the sealing of the gap, improving the pressurized air efficiency and increasing the thrust when the aircraft is in cruise flight. The low expansion high temperature alloys developed in China mainly include GH2907, GH2909, GH4783 and so on. China's newly developed GH4783 is a new antioxidant low expansion high temperature alloy, the expansion coefficient is 20% lower than GH4169 alloy, the density is 20% lower than GH4169, only 7.789/cm3, the working temperature can reach 750 ℃. The corresponding U.S. grade Inconel783 alloy has been used as various ring parts of F119-PW engine for F-22 fighter.
Their common features are good plasticity, medium strength, excellent welding performance, and good resistance to oxidation and corrosion. Mainly used for the production of engine power unit combustion chamber, the pressurized combustion chamber, aircraft tail cowl, deflector, liner cylinder and military satellite capillary tube, etc.. Most of the aero-engine combustion chamber parts are made of solid solution strengthened alloy. Recently, the engine production in order to reduce the weight of the structure, the use of time-reinforced plate alloy to manufacture combustion chamber parts, and achieved good results. The use of age-reinforced deformation of high-temperature alloys for the manufacture of the combustion chamber shell, can significantly reduce the weight of the engine, but its forming and welding than the solid solution-reinforced alloy to be difficult.
Turbine disc is a very important key part on the aero-engine. Although the turbine disk working temperature is lower than the blade, but the working environment is exceptionally complex, and in the core, rim, tenon teeth, groove bottom and web and other parts of the stress, temperature, the degree of media action are different. Therefore, the following typical requirements for turbine disk material performance: high yield strength; sufficient plasticity reserve; sufficient creep, lasting strength and plasticity; high fatigue strength and low circumference fatigue performance; good corrosion resistance, organizational stability and processability. In a word, the overall performance of the material should be good.
Most of the materials used for turbine discs are precipitation-reinforced iron-based or nickel-based deformed high-temperature alloys, and some disc parts are beginning to be prepared by powdered high-temperature alloys, but from the perspective of preparation process and cost, powdered high-temperature alloy turbine discs cannot replace deformed high-temperature alloy turbine discs.
Aero-engine cassette, rotor sealing ring and honeycomb ring parts are more often prepared by low expansion high temperature alloy at home and abroad. Low expansion alloy is the engine to achieve gap control technology, reduce gas loss and improve the thermal efficiency of irreplaceable functional structural materials. Low expansion high temperature alloy is characterized by good overall performance, high strength, low expansion coefficient, almost constant modulus of elasticity, at about 380 ℃ (Curie point) below to room temperature, the alloy thermal expansion coefficient is almost constant. Therefore, the pressurized air receiver prepared by low expansion high temperature alloy is conducive to the sealing of the gap, improving the pressurized air efficiency and increasing the thrust when the aircraft is in cruise flight. The low expansion high temperature alloys developed in China mainly include GH2907, GH2909, GH4783 and so on. China's newly developed GH4783 is a new antioxidant low expansion high temperature alloy, the expansion coefficient is 20% lower than GH4169 alloy, the density is 20% lower than GH4169, only 7.789/cm3, the working temperature can reach 750 ℃. The corresponding U.S. grade Inconel783 alloy has been used as various ring parts of F119-PW engine for F-22 fighter.
Their common features are good plasticity, medium strength, excellent welding performance, and good resistance to oxidation and corrosion. Mainly used for the production of engine power unit combustion chamber, the pressurized combustion chamber, aircraft tail cowl, deflector, liner cylinder and military satellite capillary tube, etc.. Most of the aero-engine combustion chamber parts are made of solid solution strengthened alloy. Recently, the engine production in order to reduce the weight of the structure, the use of time-reinforced plate alloy to manufacture combustion chamber parts, and achieved good results. The use of age-reinforced deformation of high-temperature alloys for the manufacture of the combustion chamber shell, can significantly reduce the weight of the engine, but its forming and welding than the solid solution-reinforced alloy to be difficult.
Precautions for welding nickel-based alloys
Nickel-based alloy applications
Cobalt-based alloys
Cobalt-based high-temperature alloys
Solid solution reinforced alloys
Casting alloys
Single crystal alloy
Nickel-based single crystal alloy
Directional crystalline high temperature alloys